The inventors discovered that an immune response to an antigen was induced in a living organism having an antigen-binding molecule administered thereto, said antigen-binding molecule including an antigen-binding domain wherein the binding activity relative to the antigen changes depending on ion concentration conditions, and an FcRn-binding domain having binding activity to FcRn in pH-neutral range conditions. The inventors also discovered that, in addition to the induced immune response to the antigen, a toxic action or a growth inhibitory action on foreign organisms, cancer cells, and the like expressing the antigen to which said antigen-binding molecule binds was also found in the living organism having the antigen-binding molecule administered thereto, said antigen-binding molecule including the antigen-binding domain wherein the binding activity relative to the antigen changes depending on ion concentration conditions, and the FcRn-binding domain having binding activity to FcRn in pH-neutral range conditions.本案發明人等發現在投予包含依離子濃度之條件對抗原之結合活性會改變之抗原結合分域及於pH中性域之條件下對FcRn有結合活性之FcRn結合分域之抗原結合分子之活體中，會誘導對該抗原之免疫反應。再者，本案發明人等發現在投予包含依離子濃度之條件對抗原之結合活性會改變之抗原結合分域及在pH中性域之條件下對FcRn有結合活性之FcRn結合分域之抗原結合分子之活體中，會誘導對該抗原之免疫反應，而且也具有對表現該抗原結合分子所結合之抗原之外來生物種或癌細胞等之傷害作用或增殖抑制作用。
